Earlier this month, a company came along and asked for a RAID 10 array. Understanding that RAID 10 is a cooler sounding way of saying RAID 1+0, I understood it as a mirror set that is striped across another mirror set. Simple enough… Just concatenate a couple of mirrors, and you’ve got RAID 10.
Indeed, RAID 10 is simply one or more RAID 1 arrays (mirrored sets) striped together (RAID 0).
RAID 1 creates an exact copy (or mirror) of all of data on two or more disks, while RAID 0 splits data evenly across two or more disks with no parity information for redundancy. By combining the two into a RAID 10 array, you are able to take advantage of the faster write speed offered by RAID 0, while protecting your data against drive failures with mirroring.
This method of RAID is pretty costly, but useful if you find yourself in a situation where you need a lot of throughput combined with a lot of data protection.
RAID10 is also a name for a newer raid type in Linux, so the precise term for what is described here is RAID 1+0.
The Linux raid10 may for some purposes be almost twice as fast as RAID 1+0, it only needs 2 drives to run effectively, and you may have odd numbers of drives in the arrau. Learn more on Linux RAID at http://linux-raid.osdl.org/index.php/Linux_Raid